On This Day in Ancient History - Eclipse

On This Day in Ancient History - May 25: The Rogue Classicist says that it may have been on this day in 585 B.C. that Thales predicted a solar eclipse. Eclipses were not yet familiar events and because during eclipses the sun disappears in the middle of the day, they could be frightening.

• To see where this event fits chronologically in the general scheme of ancient history, see Major Events in Ancient History

Herodotus 1.74 wrote about the significance of the occasion of Thales' predicted eclipse: It stopped years of fighting between Medes and Lydians [in Anatolia; see map BCc].

[1.74] Afterwards, on the refusal of Alyattes to give up his suppliants when Cyaxares sent to demand them of him, war broke out between the Lydians and the Medes, and continued for five years, with various success. In the course of it the Medes gained many victories over the Lydians, and the Lydians also gained many victories over the Medes. Among their other battles there was one night engagement. As, however, the balance had not inclined in favour of either nation, another combat took place in the sixth year, in the course of which, just as the battle was growing warm, day was on a sudden changed into night. This event had been foretold by Thales, the Milesian, who forewarned the Ionians of it, fixing for it the very year in which it actually took place. The Medes and Lydians, when they observed the change, ceased fighting, and were alike anxious to have terms of peace agreed on.

There is controversy over this. It is not clear that Thales actually knew how to predict solar eclipses and if there was a solar eclipse on that day it may have been one with a corona so that the sky would not have gone completely dark. Perhaps in the passage Herodotus writes about the momentous eclipse and the affect it had on battle, the predicted eclipse was of the lunar variety and the battle it interrupted was in the evening. (For more of this line of reasoning, see Thomas Worthen's Herodotos's Report on Thales' Eclipse, in Electronic Antiquities Volume III.)

Read more about Ancient Solar Eclipses

Presocratic Philosophers - Thales